Accepted for Publication: October 23, 2012.
Published Online: April 22, 2013. doi:10.1001/jamaneurol.2013.1507
Author Contributions:Acquisition of data: Roe. Analysis and interpretation of data: All authors. Drafting of the manuscript: All authors. Critical revision of the manuscript for important intellectual content: All authors. Statistical analysis: Roe. Administrative, technical, and material support: Roe. Study supervision: Roe.
Conflict of Interest Disclosures: None reported.
Funding/Support: The study was supported in part by the Dallas Women's Foundation (Billingsley Fund) (Dr Pascual), and the Baylor Health Care System Foundation from generous donations of Mr William Hutchison (Dr Roe).
Additional Contributions: Arnold Reuser, PhD, and Ans van der Ploeg, MD, PhD, Department of Clinical Genetics, Erasmus Universiteit, Rotterdam, the Netherlands, provided untreated samples from 26 patients for this study. Teodoro Bottiglieri, PhD, Institute of Metabolic Disease, determined SAM, SAH, methionine, homocysteine, IGF-1, IGFBP-3, and GH plasma levels. Cornelis Jakobs, PhD, Clinical Chemistry Department of the Free University of Amsterdam, Amsterdam, the Netherlands, analyzed the guanidinoacetate and creatine levels.
Additional Information: Part of this study was performed at the Institute of Metabolic Disease, Baylor University Medical Center, Dallas.